1. Technical Field
The present invention relates to a mouthpiece structure for a pressure vessel.
2. Related Art
Japanese Patent Application Publication No. JP-A-H11-13995 discloses a mouthpiece structure for a pressure vessel, which includes a liner made of a synthetic resin and constructing a vessel body and a cylindrical part communicating between an interior and an exterior of the vessel body, a cylindrical mouthpiece mounted to an inner periphery of the cylindrical part and a sealing member preventing a fluid in the vessel body from leaking through a gap between the inner periphery of the cylindrical part and an outer periphery of the mouthpiece. As shown in FIG. 13, the cylindrical part 101 of the liner 100 has a distal end surface 102. The mouthpiece 103 also has a distal end surface 104 which is adjacent to the distal end surface 102 so that both distal end surfaces 102 and 104 are coplanar. A gap between the adjacent distal end surfaces 102 and 104 serves as a leak outlet 106 through which the fluid leaking through an interface 105 between the inner periphery of the cylindrical part 101 and the outer periphery of the mouthpiece 103 flows outside the vessel. The sealing member 107 is disposed so as to close the leak outlet 106.
When the pressure of the fluid leaking through the gap between the inner periphery of the cylindrical part 101 and the outer periphery of the mouthpiece 103 is excessively large, there is a possibility that the sealing member 107 subjected to the fluid pressure would be irregularly deformed in a direction away from the leak outlet 106 while being axially pressed, as shown in FIG. 14. This irregular deformation of the sealing member 107 renders the leak outlet 106 open to the outside, resulting in loss of the sealing function.